Stockholders' Equity - Summary of Status of Outstanding Stock Options (Detail) (Stock Option [Member], USD $)	Stock Option [Member] USD ($)
Aggregate Intrinsic Value Outstanding, Beginning Balance at Dec. 31, 2012	$ 31,550
Number of Shares Outstanding, Beginning Balance at Dec. 31, 2012	35,000
Weighted Average Exercise Price Outstanding, Beginning Balance at Dec. 31, 2012	$ 8.66
Granted, Number of Shares	0
Exercised, Number of Shares	(20,000)
Expired, Number of Shares	(10,000)
Granted, Weighted Average Exercise Price	$ 0
Exercised, Weighted Average Exercise Price	$ 7.98
Expired, Weighted Average Exercise Price	$ 10.15
Aggregate Intrinsic Value Outstanding, Ending Balance at Dec. 31, 2013	0
Number of Shares Outstanding, Ending Balance at Dec. 31, 2013	5,000
Weighted Average Exercise Price Outstanding, Ending Balance at Dec. 31, 2013	$ 8.44
Granted, Number of Shares	0
Exercised, Number of Shares	(5,000)
Forfeited, Number of Shares	0
Expired, Number of Shares	0
Exercisable, Number of Shares Outstanding	0
Granted, Weighted Average Exercise Price	$ 0
Exercised, Weighted Average Exercise Price	$ 8.44
Forfeited, Weighted Average Exercise Price	$ 0
Expired, Weighted Average Exercise Price	$ 0
Exercisable, Weighted Average Exercise Price	$ 0
Exercisable, Aggregate Intrinsic Value	0
Aggregate Intrinsic Value Outstanding, Ending Balance at Dec. 31, 2014	$ 0
Number of Shares Outstanding, Ending Balance at Dec. 31, 2014	0
Weighted Average Exercise Price Outstanding, Ending Balance at Dec. 31, 2014	$ 0